Skip to main content
. 2013 Apr 4;9(4):e1003261. doi: 10.1371/journal.ppat.1003261

Figure 1. C. parvum infection increases luminal release of epithelial exosomes through activating the TLR4 signaling pathway.

Figure 1

(A) Infection stimulates luminal release of exosomes (Exs) from H69 monolayers, as assessed by electron microscopy (EM). Abundant exosome-like microvesicles were observed in the apical region of H69 monolayers following infection (arrowheads in a), with multi-vesicular bodies (MVBs) detected in the cytoplasm of infected cells (arrow in a). Only a few microvesicles were detected at the apical region of non-infected monolayers (b). Isolated apical microvesicles are 40–100 nm in size by scanning EM (c) and are positive by immunogold for exosome markers CD63 (d) and ICAM-1 (e). (B) A time-dependent apical exosome release was detected in infected H69 monolayers by nanosight tracking analysis and scanning EM. (C) Inhibition of TLR4 (by TLR4-DN transfection) and IKK2 (by SC-514), but not PI-3K (by LY294002), blocked C. parvum-induced exosome release. Scale bars = 100 nm; * p<0.05 ANOVA versus the non-infected controls; # p<0.05 ANOVA versus infected cells.